The book's protagonist, Lewis Haystoun, is persuaded to use his academic knowledge of Indian frontier to help prevent a Russian invasion. The effort transforms his character, and ultimately saves India -- but not without tragic cost.

John Buchan, the first Baron Tweedsmuir, was a Scottish novelist best known for his novel The Thirty-Nine Steps. The book was produced as a film by Alfred Hitchcock; it was the first of five books featuring the character of Richard Hannay.

John Buchan was also a Unionist politician who served as Governor General of Canada. He studied at the University of Glasgow and at Brasenose College, Oxford, winning the Newdigate prize for poetry. His friends at Oxford included Hilaire Belloc, Raymond Asquith, and Aubrey Herbert. Beginning with Prester John, he wrote thirty novels and seven collections of short stories.